<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Useful event target example</title>
    <style>
      div {
        background-color: red;
        height: 100px;
        width: 25%;
        float: left;
      }
    </style>
  </head>
  <body>
    <script>
      for(var i = 1; i <= 16; i++) {
        var myDiv = document.createElement('div');
        document.body.appendChild(myDiv);
      }
      function random(number) {
        return Math.floor(Math.random()*number);
      }
      function bgChange() {
        var rndCol = 'rgb(' + random(255) + ',' + random(255) + ',' + random(255) + ')';
        return rndCol;
      }
      var divs = document.querySelectorAll('div');
      for(var i = 0; i < divs.length; i++) {
        divs[i].onclick = function(e) {
          e.target.style.backgroundColor = bgChange();
        }
      }
    </script>
  </body>
</html>